New cement paste takes inspiration from human bone
Marie Donlon | September 30, 2024Making this possible, the researchers suggested, is that the paste features a tubular architecture inspired by the structure of human cortical bone — which forms the outer layer of the femur. As such, the cement paste’s tube-like structure increases the material’s resistance to crack propagation, and it is also being eyed as a replacement for plastic and fiber-reinforced cement-based materials.
The team was specifically inspired by the human cortical bone because it is able to resist fractures and offers the femur the strength necessary to support the body’s load. This is due to the elliptical tubular components within the human cortical bone known as osteons, which are embedded weakly in an organic matrix. This structure reportedly deflects cracks around osteons, which subsequently prevents abrupt failure and increases overall resistance to crack propagation.
To mimic this, a cement paste was formulated that features cylindrical and elliptical tubes. In the event a crack appears in a structure created with the cement paste, the tubes will trap it, thus delaying its spread to other sections of the structure. The team explained that this process of limiting the crack absorbs energy — the same energy that would have encouraged the crack to grow faster.
This dissipation of the energy reportedly offers the cement more time to resist damage, thus preventing the sudden collapse of the structure.
“One expects the material to become less resistant to cracking when hollow tubes are incorporated. We learned that by taking advantage of the tube geometry, size, shape, and orientation, we can promote crack-tube interaction to enhance one property without sacrificing another,” the team explained
An article detailing the cement paste, "Tough Cortical Bone-Inspired Tubular Architected Cement-Based Material with Disorder," which appears in the journal Advanced Materials.